New evidence from open-sea experiments shows there’s a constant shuffling of genetic material going on among the ocean’s tiny plankton. It happens via ocean-dwelling viruses, scientists report this week in the journal Science.
Conducted by biological oceanographers Sallie Chisholm and her colleagues at the Massachusetts Institute of Technology, the research is uncovering a new facet of evolution and helping scientists see how microbes exploit changing conditions, such as altered light, temperature and nutrients.
"These results tell us that even the smallest organisms show genetic variation related to the environment in which they exist," said Philip Taylor, director of the National Science Foundation (NSF)’s biological oceanography program, which funded the research.
In addition to NSF, support for the research came from the Gordon and Betty Moore Foundation and from the U.S. Department of Energy.
"Our image of ocean microbes and their role in planetary maintenance is changing," Chisholm said. "We no longer think of the microbial community as being made up of species that have a fixed genetic make-up. Rather, it is a collection of genes, some of which are shared by all microbes and contain the information that drives their core metabolism, and others that are more mobile, which can be found in unique combinations in different microbes."
The distributors or carriers of new genes, the scientists suspect, are the massive numbers of viruses also known to exist in seawater. Some of them are adept at infecting ocean microbes like Prochlorococcus, the sea’s most abundant plankton species. The ocean viruses, which carry their own genes as well as transport others, provide a way of transferring genes from old cells into new ones.
"We’re beginning to get a picture of gene diversity and gene flow in Prochlorococcus," Chisholm said. "These photosynthesizing bacteria form an important part of the food chain in the oceans, supply some of the oxygen we breathe, and play a role in modulating climate. It’s important that we understand what regulates their populations. Genetic diversity seems to be an important factor."
In one report, Chisholm and scientist Maureen Coleman suggest that gene-swapping in ocean microbes resembles the flow of genes already known to occur among disease-causing bacteria. In an ocean habitat, the exchange offers marine microbes a diverse palette of potential gene combinations, each of which might be best suited for a particular environment. "This would allow the overall population to persist despite complex and unpredictable environmental changes," said Chisholm.
A second report, by Zackary Johnson and Erik Zinser, compares where Prochlorococcus microbes are found with the conditions under which they thrive. These geographic patterns relate to environmental variables such as temperature, predators, light and nutrients.
Chisholm is trying to learn how the microbes function as a system in which they have co-evolved with each other, and with the chemistry and physics of the oceans. The studies show that all Prochlorococcus strains are very closely related, yet they display an array of physiologies and genetic diversity, Chisholm said.
"Genetic diversity is at the heart of the extraordinary stability of Prochlorococcus in the oceans, which maintain steady population sizes over vast regions of the sea," she said.
Cheryl Dybas | EurekAlert!
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences